JavaScript SCROLL BAR ลงและขึ้น ไม่รับรอง Browser Mozilla Firefox , Chrome ครับ

<DIV id="waterMark" style="position: absolute; left: 12; top: 460; width: 693; height: 19"><a href="#" onClick="window.scrollTo(0,0)"><img src="pic.jpg" border="0"></a></DIV> 
<script language="JavaScript1.2">
<!--

// กำหนดตำแหน่งของรูป
markW = 90;       // pixels wide
markH = 40;       // pixels high
markX = 99;      // percent right
markY = 99;      // percent down
markRefresh = 50; // milliseconds

// set common object reference
if (!document.all) document.all = document;
if (!document.all.waterMark.style) document.all.waterMark.style = document.all.waterMark;

wMark = document.all.waterMark.style;
wMark.width = markW;
wMark.height = markH;
navDOM = window.innerHeight; // Nav DOM flag
 
function setVals() {
 barW = 0; // scrollbar compensation for PC Nav
 barH = 0;
 if (navDOM) {
  if (document.height > innerHeight) barW = 20;
  if (document.width > innerWidth) barH = 20;
  } else {
  innerWidth = document.body.clientWidth;
  innerHeight = document.body.clientHeight;
  }
 posX = ((innerWidth - markW)-barW) * (markX/100);
 posY = ((innerHeight - markH)-barH) * (markY/100);
 }

function wRefresh() {
 wMark.left = posX + (navDOM?pageXOffset:document.body.scrollLeft);
 wMark.top = posY + (navDOM?pageYOffset:document.body.scrollTop);
 }

function markMe() {
 setVals();
 window.onresize=setVals;
 markID = setInterval ("wRefresh()",markRefresh);
 }

window.onload=markMe; // safety for Mac IE4.5

//-->
</script>